import java.io.*;
import java.util.Scanner;



public class Demo17 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入要搜索的路径：");
        String rootPath = scanner.nextLine();
        File rootFile = new File(rootPath);
        if(!rootFile.isDirectory()){
            System.out.println("要搜索的路径有误！");
            return;
        }
        System.out.println("请输入要搜索的查询词：");
        String key = scanner.next();

        //进行递归查找
        scan(rootFile,key);
    }

    private static void scan(File rootFile, String key) {
        if(!rootFile.isDirectory()) {
            return;
        }
        File[] files = rootFile.listFiles();
        if(files.length == 0 || files == null) {
            return;
        }
        for(File f : files) {
            if(f.isFile()){
                //进行后续的查询操作
                doSearch(f,key);
            }else{
                scan(f,key);
            }
        }
    }


    private static void doSearch(File f, String key) {
        //打开文件，读取文件内容，并判定文件内容是否包含 key
        StringBuilder stringBuilder = new StringBuilder();
        //因为不考虑二进制，直接按照文本的方式来处理，就直接用 Reader
        try(Reader reader = new FileReader(f)){
            char[] buffer = new char[1024];
            while(true) {
                int n = reader.read(buffer);
                if(n == -1){
                    break;
                }
                String s = new String(buffer,0,n);
                stringBuilder.append(s);
            }
        }catch (IOException e){
            e.printStackTrace();
        }
        if(stringBuilder.indexOf(key) == -1) {
            //未找到
            return;
        }
        //找到了
        System.out.println("找到匹配的文件" + f.getAbsolutePath());
    }
}
